Objectives <p>Tube feeding is a method of nutritional management that enables the maintenance of gastrointestinal function, even in patients who have difficulty with oral nutritional intake. Diarrhea is a major digestive symptom in patients receiving tube feeding, and may affect the maintenance of body weight. Therefore, this study aimed to investigate the effects of the deterioration of fecal consistency during tube feeding on body weight. We prepared 10 types of concentrated liquid diets with different contents of pectin, a dietary fiber that has been reported to maintain normal fecal consistency, and each diet was assigned to a separate group of rats with no overlap between the groups. We tube-fed each diet to gastrostomized rats for 5 days to investigate the effects of fecal consistency on body weight and nutritional status.</p> Results <p>Rats fed a pectin-containing liquid diet had lower fecal consistency scores and a greater amount and rate of body weight gain than those fed a liquid diet without pectin. Furthermore, fecal consistency showed a significant correlation with the amount and rate of weight gain. These findings suggest that the maintenance of close to normal fecal consistency under tube-feeding management contributes to body weight gain during the feeding period.</p>